Geographical, Seasonal and Diurnal Variations of Acoustic Attenuation, and Sound Speed in the Near-Surface Martian Atmosphere

This work introduces a comprehensive model of sound attenuation and speed on Mars, in light of the recent operation of several microphones on the surface of Mars. The proposed acoustic model calculates the sound speed and attenuation throughout the near-surface Martian atmosphere based on first-principles. We evaluate the effects of the seasonal and diurnal cycle of air temperature, pressure and CO₂, as well as the concentration of airborne dust on the sound attenuation. The attenuation and speed of sound are most sensitive to the air temperature and, therefore, they vary with the diurnal temperature cycle and to a lesser degree with the seasonal changes in temperature. The speed of sound also varies with the seasonal variations of the concentration of CO₂. The main outcome of this work is an acoustic model capable of computing the sound speed and attenuation for any location at the Martian surface at any time of year and any time of day.